Improvement in fire-alarms



v T. N. ROBERTS. Tire- Alarm.

No. 216,576. I Patentedlune 17, I879.

L m i 1' 2 F %V- E 1 llEL! UNITED STATES PATENT OFFIon.

THEOPHILUS N. ROBERTS, OF COLUMBIA, SOUTH CAROLINA.

IMPROVEMENT IN FIRE-ALARMS.

Specification forming part of Letters Patent No. 216.576, dated June 17,1879; application filed April 22, 1879.

To all whom it may concern:

Be it known that I, THEOPHILUS N. Ron- ERTS, of Columbia, in the countyof Richland and State of South Carolina, have invented certain new anduseful Improvements in Auto matic Fire-Alarms; and I do hereby declarethat the following is a full, clear, and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, which form part of this specification.

The nature of my invention consists in the construction and arrangementof an automatic fire-alarm, as will be hereinafter more fully set forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the annexed drawings, in which-I Figure 1 is a front view of my alarm placed upon a door-frame. Fig. 2is a longitudinal section, and Fig. 3 a cross-section, of the same.

My automatic fire-alarm may be arranged in any part of a room and in anyposition, and it is constructed as follows:

A represents a vertical rod moving in suitable guides, and its upper endformed or provided with a hammer, a. This rod is thrown upward by meansof a spring, B, so that the hammer will explode a cartridge against thecartridge-anvil G.

This cartridge anvil or holder is simply a round metal disk, betweenwhich and another disk, b, the cartridge is held.

The cartridge is annular in form, and a pin, d, is passed through thetwo disks and cartridge, and the parts held together in place by meansof a key, 0, through said pin 01, as shown.

On the rod A at a suitable point is rigidly secured a disk or collar, j,which is to catch on the short arm of a long lever, D, pivoted on astud, h, in close proximity to the vertical rod A.

The long arm of the lever D fits in a slot in a metallic guide, E, andrests upon a pin, 2', which is firmly secured in and projects from .acompound strip or thermic bar, F. When in this position the short arm ofthe lever D presses down the rod A by being on top of the disk f, sothat the hammer on will be re moved from the cartridge anvil or holder0.

In the drawings I show two thermic bars, F, but any desired number maybe used, connected in such a way that being fixed firmly by a screw orrivet, k, at one end, their other end is free to move, and to this freeend the pin t is secured.

When, by the action of heat, this thermic bar or compound strip isthrown outward the pin 2' moves with them and passes from under the longarm of the lever D, releasing the same, so that it will descend in'theslot of the guide E and fall down suddenly by the action of the spring Bon the rod A, the collar f of which rested against the under side of theshort arm of the lever. As soon as the long arm of the lever D isreleased from the pin 1',

the spring B acts suddenly and causes the hammer on on the upper end ofthe rod A to explode the cartridge.

The thermic bars are to be made so that at a certain temperaturesay, 125to 130 Fahrenheit-they will bend enough toward the side of the leastexpansible metal to cause the pin c to be drawn away from the lever D.

The temperature at which the thermic bars are to operate and produce theabove result may be regulated by means of a counter-force pressingagainst them in a direction opposite to that in which they will move orbend by the action of heat. This counter-force consists of a spring, m,fastened at one end to the under side of a dial,.G, and having the otheror free end pressing against the thermic bars.

Through the dial G is passed a screw, 1, which presses against thespring m, and by turning said screw the tension of said spring caneasily be regulated to accomplish the object soughtnamely, to regulatethe action of the thermic bars.

A pointer, n, is attached to the screw I to show on the dial at whattemperature the device has been set to act in the manner designed.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination of the thermic bars F, with pin 1', the lever D, androd A, with ham mer a and disk j, substantially as and for the anvil 0,all arranged to operate substantially purposes herein set forth. as setforth.

2. In a fire-alarm, the combination of the In testimony that I claim theforegoing as thermio bars F, lever D, rod A, spring 13, and my own Iaflix my signature in presence of anvil 0, all constructed and arrangedto opertwo Witnesses.

ate substantially in the manner described. THEOPHILUS NUNEZ ROBERTS.

3. The combination, in a fire-alarm, of the Witnesses:

thermic bars F, pin 2', spring m, dial G, pointer FITZ W. MCMASTER,

n with rod A, diskf, lever D, spring B, and D. B. DE SAUSSURE.

